Wednesday, August 30, 2006

An article in the current issue of JAMA (Journal of the American Medical Association), reporting on the recent Surgeon General's review of the health effects of secondhand smoke, brings to the forefront the controversy over whether the Surgeon General misrepresented the science in his public communications surrounding the report's release (see: Kuehn BM. Report reviews secondhand smoke risks: some scientists question risk level. JAMA 2006; 296:922-923).

The controversy stems from the press release and other ancillary materials released by the Surgeon General to accompany the report itself.

"Breathing secondhand smoke for even a short time can damage cells and set the cancer process in motion. Brief exposure can have immediate harmful effects on blood and blood vessels, potentially increasing the risk of a heart attack."

"Breathing secondhand smoke for even a short time can have immediate adverse effects on the cardiovascular system, interfering with the normal functioning of the heart, blood, and vascular systems in ways that increase the risk of heart attack."

"Even a short time in a smoky room causes your blood platelets to stick together. Secondhand smoke also damages the lining of your blood vessels. In your heart, these bad changes can cause a deadly heart attack."

These claims are markedly different from those made in the Surgeon General's report itself, which concludes that chronic exposure to secondhand smoke increases the risk for heart disease, but does not conclude (or even present evidence that) a brief exposure to secondhand smoke can cause lung cancer, heart attacks, or heart disease.

The JAMA Medical News & Perspectives article highlighted the controversy over these claims that brief exposures to secondhand smoke are enough to cause heart attacks, heart disease, and lung cancer: "More controversial [than the claims regarding the effects of chronic exposure] was the surgeon general's emphasis on the immediate risks of exposure to tobacco smoke, particularly acute cardiovascular and lung cancer risks."

"Siegel questioned the surgeon general's comments and promotional materials from Carmona's office that emphasize the acute risks. 'It's very misleading to suggest to the public that you can walk down a street and breathe in a few whiffs of smoke and be at risk of developing heart disease or lung cancer,' he said. 'It takes many years for these chronic diseases to develop, and there's simply no evidence that a brief exposure is enough to cause chronic health problems.' He said he felt the publicity materials and coverage in the media distort the evidence laid out in the report itself."

The reporter apparently sought a response to my critique from a CDC official who co-authored a 2004 commentary which suggested that brief exposure to secondhand smoke might be capable of triggering a heart attack. According to the JAMA article, that official "maintains that the evidence is strong enough that physicians should urge patients with cardiovascular disease or respiratory problems to avoid all exposure to secondhand smoke. He noted that there a large number of individuals who are unaware of the status of their cardiovascular health and may be at risk. He also said that parents need to get the unequivocal message that they should not expose their children to secondhand smoke."

The article concludes: "But Siegel said he believes public health officials should be emphasizing the well-established risks faced by individuals exposed in the workplace or at home, instead of suggesting that everyone is at risk. 'We're really risking our credibility [as public health professionals or officials] by putting out rather absurd claims that you can be exposed briefly to secondhand smoke and you are going to come down with heart disease or cancer. People are going to look at that and say that's ridiculous.'"

The Rest of the Story

I applaud JAMA for the willingness to challenge anti-smoking movement dogma and bring this issue to the attention of the public and the medical community at large. I have become convinced that it is not until the public spotlight is shined upon the misleading claims that are being made that any action will be taken to correct the problem. And this prominent exposure will help, at least to make the public and the medical community aware of what is going on.

To me, the CDC response confirms my assertion that the science has been misrepresented. Apparently in response to my critique of the Surgeon General's public communications about the report, CDC was defensive, but only so far as to emphasize that patients with existing cardiovascular disease may be susceptible to severe health effects from a brief secondhand smoke exposure. The response completely ignored my primary assertion, which is that brief exposure will not cause heart disease and lung cancer in anyone, and will not cause a heart attack in anyone without severe existing coronary artery stenosis.

In other words, it appears that CDC agrees that it is preposterous to assert that a brief exposure poses any problem for a person who does not have severe coronary artery stenosis to begin with, and CDC is unwilling to defend the Surgeon General's misleading claims. At the same time, CDC is also apparently unwilling to suggest outright that the Surgeon General went too far in his press release, remarks, fact sheet, and brochure.

This is not surprising, because it would take a lot for CDC to openly criticize the Surgeon General. Nevertheless, CDC's unwillingness to back up the Surgeon General's health claims does lend support to the validity of my arguments.

I think it is important to continue to press this issue, because it is not until the issue receives widespread public attention that any real response will be forced. On its own, the tobacco control movement has demonstrated no interest in entertaining any scientific challenge to its dogma.

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About Me

Dr. Siegel is a Professor in the Department of Community Health Sciences, Boston University School of Public Health. He has 25 years of experience in the field of tobacco control. He previously spent two years working at the Office on Smoking and Health at CDC, where he conducted research on secondhand smoke and cigarette advertising. He has published nearly 70 papers related to tobacco. He testified in the landmark Engle lawsuit against the tobacco companies, which resulted in an unprecedented $145 billion verdict against the industry. He teaches social and behavioral sciences, mass communication and public health, and public health advocacy in the Masters of Public Health program.